05/18/2010 05:12 am ET Updated May 25, 2011

Corn Ethanol -- Not Enough Bang For the Subsidized Buck

"There's a bright golden haze on the meadow

There's a bright golden haze on the meadow

The corn is as high as an elephant's eye

And the profits are climbing right up to the sky"

-- Apologies to Rodgers and Hammerstein

Corn Ethanol was once the Great Green Hope of bio-fuels. Not so much because it made sense from either an efficiency or carbon reduction standpoint, but because it made sense from an agribusiness quarterly profit report standpoint. For many years, corn-state Members of Congress have obtained massive subsidies for corn ethanol, promoting it as on it as one of the miracle fuels that would reduce carbon and lead us away from foreign oil.

Archer Daniels Midland and Cargill, two agribusiness giants, control the largest segment of corn production in the United States and have the most to gain by sticking to the Corn Standard for every possible product. Ethanol from corn holds the potential to generate enormous profits. The cost is paid in impacts on the environment. It is not at all clear that corn ethanol will reduce greenhouse gasses but it is clearly creating a tsunami of pesticide and fertilizer pollution, rolling down the Mississippi and into the Gulf of Mexico where it is creating an enormous and growing dead zone.

The corn production monoculture disrupts the natural balance of carbon in soil. Corn is grown as a row crop. This, and other aspects of industrial scale farming, creates problems with topsoil loss. Because of the increasing price of corn due to its demand as a fuel, less crop rotation is occurring to renew soil. Organic material decomposing back into the soil replaces carbon in the soil. Plowing and tilling the soil releases carbon into the atmosphere. When you look at the huge scale of manufacturing corn as a fuel, you can begin to see the seriousness of the soil/carbon problem.

The pesticides and fertilizers used to maximize the crop yield of corn don't just sit harmlessly on the land. They wash into watersheds, along with topsoil, and make their way to the ocean. Remember, the companies that grow this corn are interested in the highest possible yield per acre to generate the highest possible profits for stock holders. This means that every farming method which increases yield at a low cost is employed. Environmental consequences do not have a negative effect on the corporation's profit. Organic farming and sustainable farming methods would increase the cost of production so they are never going to happen within the current context. More corn, more ethanol, more pollution, more money.

But the fundamental problem with corn ethanol, the thing that makes it a non-starter in practical terms, is that it is not at all clear that corn ethanol reduces green house gases. That's the bottom line of this problem. The most optimistic science shows only marginal benefit to using corn for fuel and there is nothing like a consensus that the most optimistic science is the most realistic science. Whatever marginal, theoretical benefit comes form corn ethanol comes at a huge environmental cost. Yet it continues to be the crop of choice for bio-fuels among the largest agribusiness corporations.

The good news is that there are other potential sources of cellulosic ethanol that would be much more efficient, be more topsoil friendly and would not require pesticides and fertilizer. They don't fit as easily into an existing agribusiness business model, so they are not getting massive government subsidies.

Perennial grasses such as switch grass and Miscanthus can be grown more easily, are shown to be more effective generators of energy, reduce erosion and actually restore carbon to the soil throughout their life cycle.

Cellulosic ethanol holds some potential to reduce green house gasses and reduce our dependence on imported oil. But our objective has to be finding the most energy-efficient plant material at the lowest cost to our environment. As long as the agribusiness lobby continues to influence Congress to subsidize corn, we will not see the advances in this area that we should. We'll just be growing a lot of corn and sending a lot of polluted, nitrogen rich top soil down the Mississippi.